1 /* 2 * drivers/cpufreq/cpufreq_stats.c 3 * 4 * Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>. 5 * (C) 2004 Zou Nan hai <nanhai.zou@intel.com>. 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 12 #include <linux/cpu.h> 13 #include <linux/cpufreq.h> 14 #include <linux/module.h> 15 #include <linux/slab.h> 16 17 static DEFINE_SPINLOCK(cpufreq_stats_lock); 18 19 struct cpufreq_stats { 20 unsigned int total_trans; 21 unsigned long long last_time; 22 unsigned int max_state; 23 unsigned int state_num; 24 unsigned int last_index; 25 u64 *time_in_state; 26 unsigned int *freq_table; 27 unsigned int *trans_table; 28 }; 29 30 static int cpufreq_stats_update(struct cpufreq_stats *stats) 31 { 32 unsigned long long cur_time = get_jiffies_64(); 33 34 spin_lock(&cpufreq_stats_lock); 35 stats->time_in_state[stats->last_index] += cur_time - stats->last_time; 36 stats->last_time = cur_time; 37 spin_unlock(&cpufreq_stats_lock); 38 return 0; 39 } 40 41 static void cpufreq_stats_clear_table(struct cpufreq_stats *stats) 42 { 43 unsigned int count = stats->max_state; 44 45 memset(stats->time_in_state, 0, count * sizeof(u64)); 46 memset(stats->trans_table, 0, count * count * sizeof(int)); 47 stats->last_time = get_jiffies_64(); 48 stats->total_trans = 0; 49 } 50 51 static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf) 52 { 53 return sprintf(buf, "%d\n", policy->stats->total_trans); 54 } 55 56 static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf) 57 { 58 struct cpufreq_stats *stats = policy->stats; 59 ssize_t len = 0; 60 int i; 61 62 if (policy->fast_switch_enabled) 63 return 0; 64 65 cpufreq_stats_update(stats); 66 for (i = 0; i < stats->state_num; i++) { 67 len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i], 68 (unsigned long long) 69 jiffies_64_to_clock_t(stats->time_in_state[i])); 70 } 71 return len; 72 } 73 74 static ssize_t store_reset(struct cpufreq_policy *policy, const char *buf, 75 size_t count) 76 { 77 /* We don't care what is written to the attribute. */ 78 cpufreq_stats_clear_table(policy->stats); 79 return count; 80 } 81 82 static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf) 83 { 84 struct cpufreq_stats *stats = policy->stats; 85 ssize_t len = 0; 86 int i, j; 87 88 if (policy->fast_switch_enabled) 89 return 0; 90 91 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n"); 92 len += snprintf(buf + len, PAGE_SIZE - len, " : "); 93 for (i = 0; i < stats->state_num; i++) { 94 if (len >= PAGE_SIZE) 95 break; 96 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ", 97 stats->freq_table[i]); 98 } 99 if (len >= PAGE_SIZE) 100 return PAGE_SIZE; 101 102 len += snprintf(buf + len, PAGE_SIZE - len, "\n"); 103 104 for (i = 0; i < stats->state_num; i++) { 105 if (len >= PAGE_SIZE) 106 break; 107 108 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ", 109 stats->freq_table[i]); 110 111 for (j = 0; j < stats->state_num; j++) { 112 if (len >= PAGE_SIZE) 113 break; 114 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ", 115 stats->trans_table[i*stats->max_state+j]); 116 } 117 if (len >= PAGE_SIZE) 118 break; 119 len += snprintf(buf + len, PAGE_SIZE - len, "\n"); 120 } 121 if (len >= PAGE_SIZE) 122 return PAGE_SIZE; 123 return len; 124 } 125 cpufreq_freq_attr_ro(trans_table); 126 127 cpufreq_freq_attr_ro(total_trans); 128 cpufreq_freq_attr_ro(time_in_state); 129 cpufreq_freq_attr_wo(reset); 130 131 static struct attribute *default_attrs[] = { 132 &total_trans.attr, 133 &time_in_state.attr, 134 &reset.attr, 135 &trans_table.attr, 136 NULL 137 }; 138 static struct attribute_group stats_attr_group = { 139 .attrs = default_attrs, 140 .name = "stats" 141 }; 142 143 static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq) 144 { 145 int index; 146 for (index = 0; index < stats->max_state; index++) 147 if (stats->freq_table[index] == freq) 148 return index; 149 return -1; 150 } 151 152 void cpufreq_stats_free_table(struct cpufreq_policy *policy) 153 { 154 struct cpufreq_stats *stats = policy->stats; 155 156 /* Already freed */ 157 if (!stats) 158 return; 159 160 pr_debug("%s: Free stats table\n", __func__); 161 162 sysfs_remove_group(&policy->kobj, &stats_attr_group); 163 kfree(stats->time_in_state); 164 kfree(stats); 165 policy->stats = NULL; 166 } 167 168 void cpufreq_stats_create_table(struct cpufreq_policy *policy) 169 { 170 unsigned int i = 0, count = 0, ret = -ENOMEM; 171 struct cpufreq_stats *stats; 172 unsigned int alloc_size; 173 struct cpufreq_frequency_table *pos, *table; 174 175 /* We need cpufreq table for creating stats table */ 176 table = policy->freq_table; 177 if (unlikely(!table)) 178 return; 179 180 /* stats already initialized */ 181 if (policy->stats) 182 return; 183 184 stats = kzalloc(sizeof(*stats), GFP_KERNEL); 185 if (!stats) 186 return; 187 188 /* Find total allocation size */ 189 cpufreq_for_each_valid_entry(pos, table) 190 count++; 191 192 alloc_size = count * sizeof(int) + count * sizeof(u64); 193 194 alloc_size += count * count * sizeof(int); 195 196 /* Allocate memory for time_in_state/freq_table/trans_table in one go */ 197 stats->time_in_state = kzalloc(alloc_size, GFP_KERNEL); 198 if (!stats->time_in_state) 199 goto free_stat; 200 201 stats->freq_table = (unsigned int *)(stats->time_in_state + count); 202 203 stats->trans_table = stats->freq_table + count; 204 205 stats->max_state = count; 206 207 /* Find valid-unique entries */ 208 cpufreq_for_each_valid_entry(pos, table) 209 if (freq_table_get_index(stats, pos->frequency) == -1) 210 stats->freq_table[i++] = pos->frequency; 211 212 stats->state_num = i; 213 stats->last_time = get_jiffies_64(); 214 stats->last_index = freq_table_get_index(stats, policy->cur); 215 216 policy->stats = stats; 217 ret = sysfs_create_group(&policy->kobj, &stats_attr_group); 218 if (!ret) 219 return; 220 221 /* We failed, release resources */ 222 policy->stats = NULL; 223 kfree(stats->time_in_state); 224 free_stat: 225 kfree(stats); 226 } 227 228 void cpufreq_stats_record_transition(struct cpufreq_policy *policy, 229 unsigned int new_freq) 230 { 231 struct cpufreq_stats *stats = policy->stats; 232 int old_index, new_index; 233 234 if (!stats) { 235 pr_debug("%s: No stats found\n", __func__); 236 return; 237 } 238 239 old_index = stats->last_index; 240 new_index = freq_table_get_index(stats, new_freq); 241 242 /* We can't do stats->time_in_state[-1]= .. */ 243 if (old_index == -1 || new_index == -1 || old_index == new_index) 244 return; 245 246 cpufreq_stats_update(stats); 247 248 stats->last_index = new_index; 249 stats->trans_table[old_index * stats->max_state + new_index]++; 250 stats->total_trans++; 251 } 252